Think you had problems with mice.
Last car we had , a Volvo XC 60, started to misbehave, strange things happened with the electrics, air bag light kept on coming on saying airbags needed servicing etc .
Took it to the garage, but they couldnt do anything , it needed to have a full diagnostic check.
We were advised of an auto electrician who did home visits, really good reputation. He arrived, plugged in, pushed buttons on computer etc, then removed the back seat and carpets.
Underneath there was a large wadding of chewed up sound insulation, mouse droppings and a lot of wiring that had been chewed up… little barstewards .He cleaned it all up and sorted out the chewed up wires ,replacing it all.
Cost a hundred quid .
I asked if he had seen anything like it before.. he said it was a fairly common thing with rural vehicle owners . Buggered if I know how the little sods got in there unless thew were hidden in my fishing tackle bag , even then my fishing gear never had any sign of mouse damage .
Dave